1. Field of the Invention
The invention relates to a device and a method for fixing a gain or attenuation factor for a gain or attenuation element.
2. Discussion of the Background
To achieve a time synchronization between transmitting and receiving radio devices, a special sequence of synchronization-data symbols, a so-called synchronization hop, as illustrated in FIG. 1, is preferably transmitted. In the receiving radio device, the received synchronization-data symbols are correlated with the reference synchronization-data symbols known to the receiving radio device in order to determine a time reference of the synchronization-data symbols received. The time of the correlation maximum represents a reference time. The synchronization-data symbols are preferably transmitted using a frequency-hop method with a linear modulation method. This leads to a variation of the envelope curve of the sequence of synchronization-data symbols, as indicated by the grey hatched area in FIG. 1.
The signal level of the received signal of the radio device also varies as a result of the variation of the envelope curve, the amplitude distortion in the transmission channel and superposed amplitude noise. A change in the signal level of the received signal leads to the activation of an automatic gain control (Automatic Gain Control (AGC)) of the individual gain elements or respectively attenuation elements, which are adjustable with regard to their gain factor or attenuation factor in the input signal pathway of the radio device. An AGC control is described, for example, in U.S. Pat. No. 7,853,224 B2. The change of the envelope-curve level of the received signal once again disadvantageously leads to an incorrect detection of the received signal.